pooor gas mileage

[milkman672042000]

ever since it has gotten cold here my geo is only getting around 35 from the usual 48 to 50 it idles very rough im at a lost at what to do

[rruddfan21]

how does it run when it gets to operating temperature??? maybe you could check you engine coolant temp sensor??? dunno buddy hope that helps

[tude123]

According to the our Twin Cities, Minnesota radio talk-show car expert; a 10 to 15% loss in gas mileage during the winter is normal due to a change in gasoline formula. I had the same question because my gas mileage decreases from 6 to 8 mpg during the winter every year. I also wonder if driving with the extra wattage of driving with headlights constantly on and running the heater blower (300watts worth if I remember right!) would add to the drop in gas mileage...

[milkman672042000]

in the summer after it got hot it would idle up and down now that it has gotten cold outside it idles really rough almost as if it is missing

[tude123]

Are you getting a fault codes along with your poor idling?

[milkman672042000]

there are no lights that come on and the temperature gauge seems to work fine but very sluggish ever since the weather has gotten cold idles rough and sounds completely different from this summer like it might be missing

[Geogriff]

Originally Posted by milkman672042000

there are no lights that come on and the temperature gauge seems to work fine but very sluggish ever since the weather has gotten cold idles rough and sounds completely different from this summer like it might be missing

Hi Milkman,Owned GEOs for several years.It's a common problem with them.The Air intake has a IAT (inlet air Temp) sensor That richens up the carb/injector for a choke effect. As well as the Coolant temp running below 190 keeps it in the rich condition. A few people who "hot rod" them run 180 or lower thermostats to trick the ECU to thinking it's still cold so it needs more fuel to bring temp up. Check for any vacuum lines that may be broken/cracked or off. easiest way is after it's warmed up spray some starting fluid or carb cleaner around the vacuum hoses & fittings & see if the rpm jumps up. As long as it's cold the thermostat & IAT are dumping more gas in than what you want. Hope this sheds some light.